(bound form) base; foundation / (bound form) radical (chemistry) / (bound form) gay (loanword from English into Cantonese, Jyutping: gei1, followed by orthographic borrowing from Cantonese)
基
=
其
+
土
:
Joan of Arc (ji) has to repair the watchtower (其) In front of the space station (Ø1). The tower needs a new foundation (基), and because it is floating in outer space, Joan of Arc can just add some dirt (土) to its base (基) to create a new foundation.
址
=
土
+
止
:
James II of England (zh) found some old documents describing the location (址) of an old pirate treasure chest inside the space station (Ø3). He marks off the territory with a barrier (止) and builds up a huge pile of earth (土) as he digs for the treasure.